%I A174600
%S A174600 1,1,1,0,1,1,0,1,1,1,1,0,1,1,1,1,0,0,1,1,1,0,1,1,0,1,1,1,0,1,1,0,0,1,1,1,
%T A174600 1,0,0,1,1,0,1,1,1,1,0,0,1,1,1,0,1,1,1,0,1,1,0,0,1,1,0,1,1,1,0,1,1,0,0,1,
%U A174600 1,1,0,1,1,1,1,0,0,1,1,0,0,1,1,0,1,1,1,1,0,0,1,1,0,0,1,1,1,0,1,1,1,0,1,1
%N A174600 T(n,k) = 1 if the sum of +-k..+-n with arbitrary signs never equals zero, = 0 otherwise (lower triangle)
%Y A174600 Related to A063865
%o A174600 # awk
%o A174600 {for(n=1; n<10; n++)for(k=1; k<=n; k++)print ++i,T(n,k);}
%o A174600 function T(n,k) {
%o A174600 if(int((n+1)/2)%2!=int(k/2)%2)return 1;
%o A174600 else if((n-k)%2==0) {
%o A174600 if(k>((n-k)/2)^2)return 1;
%o A174600 else return 0;
%o A174600 }
%o A174600 else return 0;
%o A174600 }
%H A174600 R. H. Hardin, <a href="b174600.txt">Table of n, a(n) for n=1..4950</a>
%K A174600 nonn,tabl
%O A174600 1,1
%A A174600 Ron Hardin (rhhardin(AT)att.net) Mar 23 2010, with formula and reference from Franklin T. Adams-Watters and Olivier Gerard, on the Sequence Fans Mailing list.

